This is an optional Kyosho Aluminum Rear Hub Carrier Set, and is intended for use with Kyosho MP7.5 and MP777 based 1/8 buggies, the ST-R and ST-RR 1/8 trucks, as well as the Inferno GT and GT2 vehicles. These hubs will dramatically increase the strength of the rear suspension and at the same time provide more stable geometry. The included bearing inserts make bearing installation and removal easy and the hubs use setscrews to hold the hinge pins in place.